Light traveling though air strikes the surface of the four different materials shown. which material reflects light but does not refract it?

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.

the answer to this is proletariats.

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